This invention relates to a timing chain drive and more particularly to an improved arrangement for driving an overhead mounted camshaft from the crankshaft of an internal combustion engine.
As is well known, internal combustion engines operating on the four-stroke cycle normally employ poppet valves that are operated by a camshaft that is driven at one-half crankshaft speed by a suitable timing mechanism. Advantageously, the camshaft is mounted in the cylinder head for operating overhead valves. Frequently, there are two camshafts employed for operating the valves associated with a single cylinder. Because of the timing relationship between the crankshaft speed and the camshaft speed, the sprockets or gears on the respective camshaft and crankshaft determine the overall size of the engine. It is, of course, desirable to maintain a very compact construction for the engine but this is difficult if not impossible with the type of timing drives previously employed.
It is, therefore, a principal object of this invention to provide an improved camshaft driving arrangement for an internal combustion engine.
It is another object of this invention to provide an improved and compact drive for the overhead camshafts of an internal combustion engine.